The boy's father, 54-year-old Charles Runge remains hospitalized in critical condition. Authorities say he sustained significant burns while trying to go back into the burning home to rescue his family.

Charles' girlfriend, 52-year-old Susan Nash, died in the fire. A funeral mass was held for her Thursday.

The Hunterdon County Prosecutor's Office says the cause of Sunday's blaze appears to be accidental and is related to a fireplace that was used to heat the home.